[Haskell-cafe] Re: Tail Recursion within the IO Monad

Rob Hoelz wrote:

"Brandon S. Allbery KF8NH" wrote:

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On May 16, 2007, at 12:23 , Rob Hoelz wrote:

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And as long as I'm asking, is there some kind of monadic function composition operator? I'd like to clean up the above with something like peekCString . peek . linked_list_getdata... (=<<)?

Thanks for the reply; I can't believe I missed that one! But while looking over the documentation, completely humbled, I discovered sequence, which allows me to write my code cleanly! Thanks for the help!

sequence still isn't tail-recursive, although sequence_ is. If you want a tail-recursive sequence, the only way to do it is like this: sequence' :: [IO a] -> IO [a] sequence' ms = do let as = map unsafePerformIO ms foldr seq (return ()) as return as although that's likely to be a lot slower, too. Cheers, Simon